Evaluates: MAX17559 MAX17559 Evaluation Kit General Description Quick Start The MAX17559 EV kit is a proven design to evaluate Required Equipment the dual synchronous step-down regulator that provides MAX17559 EV kit independent 3.3V and 5V outputs capable of driving 8A 4.5V to 60V, 15A DC power supply and 15A loads from the 6V to 60V input-voltage range. Operating the two regulators 180 out-of-phase signicfi antly Loads capable of sinking 8A and 15A reduces the peak input ripple current, allowing the use Two digital voltmeters (DVM) of smaller, less expensive components, while minimizing parts count. The EV kit features adjustable input undervoltage Procedure lockout, soft-start/stop time, and current-limit threshold, The EV kit is fully assembled and tested. Follow the steps as well as selectable PWM/DCM modes, foldback/latchoff below to verify board operation. Caution: Do not turn on current limit, and independent open-drain PGOOD signals. the power supply until all connections are completed. By disabling channel 2, the evaluation kit is capable of 1) Set the power supply voltage to 24V and ensure that operating from a lower input supply (4.5V to 60V), providing the DC power supply is disabled. a single 3.3V output driving up to 15A. 2) Set one load to 8A and the other load to 15A. Disable the loads in the case of electronic loads (leave the Benefits and Features loads unconnected in case of resistor loads. Ensure 6V to 60V Input Range that the resistor power ratings are high enough to Output Rails: VOUT1: 3.3V/15A, VOUT2: 5V/8A dissipate the output voltages). 150kHz Switching Frequency 3) Connect the positive terminal of the power supply to Independent Enable Inputs the VIN connector and the negative terminal to the PGND connector, which is nearest to VIN connector. Independent Adjustable Soft-Start Time 4) Connect one digital voltmeter across the VOUT1 Configurable Tracking Operation connector and the nearest PGND connector, with Selectable PWM/DCM Modes of Operation the positive terminal of the DVM connected to the Fixed 180 Out-of-Phase Operation VOUT1 connector. Selectable Foldback/Latchoff Current Limit 5) Connect the other digital voltmeter across the VOUT2 connector and the nearest PGND connector, Programmable Current-Limit Threshold with the positive terminal of the DVM connected to Independent PGOOD Outputs the VOUT2 connector. Overcurrent, Overvoltage, and Overtemperature 6) Verify that the shunts are connected between pins Protection 1-2 of the JU1 and JU2 jumpers to select default settings Proven PCB Layout of the EV kit Fully Assembled and Tested 7) Turn on the DC power supply. 8) Verify that the digital voltmeters display the expected voltages (3.3V1% on VOUT1 and 5V1% on VOUT2). 9) Enable the electronic load (connect the load in the Ordering Information appears at end of data sheet. case of resistor load). 10) Verify that the voltmeters display the expected volt- ages (3.3V1% on VOUT1 and 5V1% on VOUT2). 19-7696 Rev 0 6/15MAX17559 Evaluation Kit Evaluates: MAX17559 time of V and V are calculated based on the OUT1 OUT2 Detailed Description of Hardware following equation: The MAX17559 EV Kit provides dual 3.3V/15A and 5V/8A outputs from a 6V to 60V input supply. By disabling channel 0.8V 2, the EV kit provides a 3.3V output to drive up to 15A t C SS SS 5A from a low 4.5V to 60V input voltage. The EV Kit is preset to 150kHz and operates 180 out-of-phase for optimum The default soft-start/stop time of V or V is OUT1 OUT2 efficiency and component size. approximately 10.8ms at 68nF soft-start/stop capacitor. The EV kit implements an optional sub-circuit, R13R18, Enable/Undervoltage-Lockout R28, D7, and JU1, JU2 to enable/disable the output at Level (EN ) a desired input UVLO, as well as soft-start/stop power sequence. Resistors R35 and R36 are selected different The device can be independently started up or shut values to configure the EV kit operating in DCM/PWM mode down by manipulating the EN1 and EN2 pins. Leave EN and foldback/latchoff, current-limit mode, respectively. unconnected for a default enable controller. Place shunts across pins 1-2 of JU1 and JU2 to enable each control- Configuring the Output Voltages (VOUT1, VOUT2) ler through the input UVLO formed by resistor-dividers. The device output voltages (V and V ) can be OUT1 OUT2 Connect a resistor-divider from V to EN and EN to IN adjusted between 0.8V to 24V through sets of feedback GND to program the UVLO threshold for the correspond- resistor-dividers R19,R20 and R23,R24 by the following ing controller. The EN pin can be programmed to 1.25V formula: (typ) to detect UVLO at a desired input voltage to enable/ disable the corresponding controller with 50mV (typ) R19 R23 R20 and R24 hysteresis. Place jumpers across pins 2-3 of JU1 and JU2 VV OUT1 OUT2 to disable the controllers. Table 1 shows all configurations (1) ( 1) 0.8 0.8 of jumpers to enable/disable each of controllers. Please refer to MAX17559 IC data sheet to select the R19 Select R14 (R18 for OUT2) below 10K and calculate R13 and R23 values, changing compensation components, as (R17) based on the following equation: well as output capacitors for setting new output voltages. R14(V 1.25) INUVLO Soft-Start/Stop (SS ) R13 = 1.25 The device offers an SS pin to connect a capacitor to GND to adjust the soft-start/stop time during startup and shut- where V is the input voltage at which the controller INUVLO down. An internal 5A current source charges/discharges is required to turn on. the capacitor at the SS pin, providing a linear ramping voltage for output voltage reference. The soft-start/stop Table 1. Enable Control (JU1, JU2) JUMPER SHUNT POSITION EN MAX17558 OUTPUT Not installed Unconnected Enabled Connected to the midpoint of Enabled, UVLO level is set by the JU1 1-2 input UVLO divider resistor divider from VIN to GND. 2-3 Connected to GND Disabled Not installed Unconnected Enabled Connected to the mid-point of Enabled, UVLO level is set by the JU2 1-2 input UVLO divider resistor divider from VIN to GND. 2-3 Connected to GND Disabled Maxim Integrated 2 www.maximintegrated.com = = =